Atrial myxoma

An atrial myxoma is a noncancerous tumor in the upper left or right side of the heart. It grows on the wall (atrial septum) that separates the two sides of the heart.

Causes

A myxoma is a primary heart (cardiac) tumor. This means that the tumor started within the heart. Most heart tumors start somewhere else.

Primary cardiac tumors are rare. Myxomas are the most common type of these rare tumors. About 75% of myxomas occur in the left atrium of the heart, usually beginning in the wall that divides the two upper chambers of the heart. The rest are in the right atrium. Right atrial myxomas are sometimes associated with tricuspid stenosis and atrial fibrillation.

Myxomas are more common in women. About 10% of myxomas are passed down through families (inherited). Such tumors are called familial myxomas. They tend to occur in more than one part of the heart at a time, and often cause symptoms at a younger age than other myxomas.

Symptoms

Symptoms may occur at any time, but most often they accompany a change of body position. Symptoms may include:

These general symptoms may also mimic those of infective endocarditis.

Signs and tests

The health care provider will listen to the heart with stethoscope. A "tumor plop" (a sound related to movement of the tumor), abnormal heart sounds, or murmur may be heard. These sounds may change when the patient changes position.

Right atrial myxomas rarely produce symptoms until they have grown to be at least 13 cm (about 5 inches) wide.

Although a myxoma is not cancer, complications are common. Untreated, a myxoma can lead to an embolism (tumor cells breaking off and traveling with the bloodstream), which can block blood flow or cause the myxoma to grow in another part of the body. Myxoma fragments can move to the brain, eye, or limbs.

If the tumor grows inside the heart, it can block blood flow through the mitral valve and cause symptoms of mitral stenosis. This may require emergency surgery to prevent sudden death.

Calling your health care provider

Tell your health care provider if there is any family history of myxomas or if you have symptoms of atrial myxoma.

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